1. Field of the Invention
The invention relates generally to an apparatus and method for high-pressure die casting.
2. Related Art
High-pressure die casting is oftentimes used to manufacture parts formed of metal or another material. A high-pressure die casting apparatus typically includes a first die half and a second die half each presenting a molding surface. When the die apparatus is closed, the molding surfaces present a mold cavity therebetween. A shot sleeve extends through one of the die halves and conveys molten material to the mold cavity. In a conventional high-pressure die casting process, the molten material is not poured into the shot sleeve until the die apparatus is closed, otherwise the molten material will flow out of the shot sleeve causing a potential safety issue and causing the casting process to fail.
U.S. patent application Publication No. 2009/0211724 (the '724 publication) discloses a die casting device and method providing reduced cycle times and thus an advantage over the conventional casting process. The die casting device includes molding surfaces presenting a mold cavity therebetween, a shot sleeve having an opening along one of the molding surfaces, and a slider disposed along the molding surface adjacent the opening of the shot sleeve. The slider at least partially seals the opening while molten material is poured into the shot sleeve. Thus, the molten material can be poured into the shot sleeve when the die casting device is still open, which reduces the cycle time. After the solidified part is ejected from the device and the excess material is removed from the shot sleeve, the method includes spraying a lubricant onto the molding surfaces in preparation for the next casting cycle. However, there are several potential problems associated with the device and method described in the '724 publication which could increase cycle time and decrease productivity. For example, the slider could malfunction and may not correctly align with the opening of the shot sleeve. The slider could also cause excessive material flashes or blockage along the opening of the shot sleeve, due to high-pressure and dynamic impact of the material against the slider. In addition, the lubricant sprayed onto the molding surfaces could become entrapped in the shot sleeve.